Councils redesigning themselves as public services commissioners have a unique opportunity to make sure those services really are the ones their communities want, according to Sir Merrick Cockell, chair of the Local Government Association.

At a Guardian local government leaders debate later this week he will claim that councils need to "sharpen their skills" to avoid commissioning exactly the same services they have provided themselves for decades.

Speaking ahead of the debate, Cockell said: "In the past we would contract our services but we would determine what those services were. Often they would be very similar to the ways we have done it in-house, in a rather traditional way. This is an opportunity to ask questions. We need to see that what communities want and what can be offered is joined together, taking the opportunity to make sure that services are right."

The debate, hosted by Guardian Professional's local government network and to be held at the Guardian's London headquarters on 19 April, will address the changing role of local government in England. Almost 70 local government managers and policymakers will take part in the discussion.

Cockell will use the opportunity to warn that negative attitudes towards commissioning services from the private sector could hold back the process of transforming local government.

"I think one could say that shouldn't happen but I think that is inevitable. Some of that is based on perceptions, and some based on past experience where a form of contracting simply hasn't worked," he explained. "We all have become conditioned to be quite risk averse, and shifting that while taking our communities into a world where there is perhaps a bit more risk is hard."

However, acting as a commissioner rather than designer of public services could also lead to improved monitoring and better democratic representation for local communities. No longer paradoxically criticising the services they helped create, council officers can review the service on the basis of the contract in hand.

"We can act in a different way as commissioners. That's quite a liberating place to be in. For commissioners, it frees them from saying this is a council service and they can take a step back," Sir Merrick said.

As leader of the borough of Kensington and Chelsea, he is interested in the concept of new mutual services being spun out of local government. But he warned that most councils would watch and wait to see the progress of others rather than take the first step themselves.

"It takes time. It can't be done quickly, and one of the most difficult things is taking staff with you. Without them it can't be done," he added.